This is a tangle-shaped silver ring with rainbow moonstone, purchased several years ago from a specialty shop that only deals in high-quality silver. It's a one-of-a-kind piece. I've worn it a few times and stored it in a zip-lock bag, so I don't think there's any deterioration. It has a schiller effect, but I couldn't capture it well in the photos (>_<) The size is adjustable! It's currently around size 13.